The patented shape supports the hand in an upright, neutral position, which generally prevents the forearm from twisting. The Evoluent Vertical Mouse can alleviate or prevent carpal tunnel syndrome (nerve compression in the hand). It features an improved thumb rest and now has two thumb buttons. The laser sensor is adjustable, and it comes with a mini USB receiver. The powerful and intuitive driver offers 6 buttons as well as a DPI switch button.